Can a range hood vent have a 90 degree bend and vent out the wall?

Question

I know I need to check my local codes before proceeding with this. that will be done but I first wanted to ask this community for advice.

i'm going to have my kitchen gutted to the studs in a couple weeks and the walls will be open. the kitchen has vaulted ceilings and a recirculating range hood (currently). I would like to install a vent that goes outside as I will be installing a LP gas range.

the wall where the vent would be goes up about 14ft. to the roof. there is also a skylight directly above the area where the range is leaving very little, if any room for an exhaust vent.

what I would like to do is installed a box shaped vent between the studs in the wall going up about 5-6ft. then exiting 90-degrees out.

i've seen similar 90-degree gas exhausts on houses in the area. Then again, I do live in the mountains though where many people do not get permits and have things checked out.

So my question is: Is it safer/better to have a straight vent through the roof? Or is a 90-degree exhaust through the wall acceptable?

Answer 1

In general, yes an exhaust vent (or any vent) can turn corners. But there are many other factors to consider.

Different vent materials or dimensions resist air differently. Different ways of turning corners resist air differently. The best place to start looking for info on this is the vent installation manual. It will talk about different ways to construct vents, what types of ducting corners can be used, and what size of ducting you need. It will talk about how many feet of vent the blower can push through, and how many feet to count a corner as (typically 5').

So you know, the shallow box vents have poor airflow. And you have to consider getting through the top-plate of the wall, which would create a huge weak point. When we built our kitchen I was hoping for in-wall ducting. Instead, the installers had to put a 10" circular duct up through the middle of the cabinet above the stove.